Bacteria adopt a morphology that is adapted to the selective pressure of their environment, which makes it an essential feature for their survival. This shape is intimately linked to the synthesis of the bacterial cell wall. In Gram + bacteria, such as Streptococcus pneumoniae, the cell wall is mainly composed of a thick layer of peptidoglycan (PG), which forms a three-dimensional network of sugars and peptides at the surface of the cell. Although the PG synthesis machineries, called divisome and elongasome, have been identified for decades, their dynamics of assembly and remodeling of the bacterial cell wall in time and space remain enigmatic. In order to study these processes at the nanometer scale, researchers of the PG group in collaboration with the PIXEL team of IBS (D. Bourgeois), a chemist from the DPM (Y-S. Wong) of Grenoble and the B3P team of the MMSB in Lyon (C. Grangeasse), have developed a labeling technique for newly synthesized PG using bio-orthogonal chemistry (click chemistry) coupled with high resolution fluorescence imaging (dSTORM), and in silico modeling. This pioneering work describes the dynamics of PG synthesis in the pneumococcus with previously inaccessible details. In the future, this approach could be used to elucidate the mode of action of new antibiotics, and could also be adapted to the study of cellular processes in all fields of life.
Nanoscale dynamics of peptidoglycan assembly during the cell cycle of Streptococcus pneumoniae. Trouve J, Zapun A, Arthaud C, Durmort C, Di Guilmi AM, Söderström B, Pelletier A, Grangeasse C, Bourgeois D, Wong YS, Morlot C. Current Biology 2021 ; S0960-9822(21)00576-5
Contact : Cécile Morlot, (IBS/Pneumococcus Group)